The long-term goal of this project is to examine the biochemical, endocrinological and toxicological effects of drugs which influence catecholaminergic neurons in the central nervous system. Particular attention will be directed toward the actions of drugs which influence nigrostiatal, mesolimbic, tuberoinfundibular and incertohypothalamic neuronal systems. Efforts will be made to determine what functions each of these neuronal systems regulate and, in turn, what regulates the activity of these neurons.